Method of manufacturing light emitting device and light emitting device

Abstract

A method of manufacturing a light emitting device includes: providing a light emitting device in which a first and second semiconductor laser elements are connected in series; performing a first measurement that includes supplying current to the first semiconductor laser element to measure at least one property of the first semiconductor laser element, and supplying current to the second semiconductor laser element to measure at least one property of the second semiconductor laser element; supplying current to the first and second semiconductor laser elements for a length of time; performing a second measurement that includes supplying current to the first semiconductor laser element to measure the at least one property of the first semiconductor laser element, and supplying current to the second semiconductor laser element to measure the at least one property of the second semiconductor laser element, and evaluating the first and second semiconductor laser elements.

What is claimed is: 
     
       1. A method of manufacturing a light emitting device, the method comprising, in this order:
 providing the light emitting device, which comprises:
 a base comprising a first wiring, a second wiring, and a third wiring, 
 a first semiconductor laser element electrically connected to the first wiring and the second wiring, at an upper surface side of the base, and 
 a second semiconductor laser element electrically connected to the second wiring and the third wiring, at the upper surface side of the base, 
 wherein the base comprises a frame surrounding the first semiconductor laser and the second semiconductor laser in a top view, 
 wherein the first wiring comprises:
 a first part that is located at an upper surface of the base at a location inward of the frame, and 
 a second part that is exposed at a location outward of the frame in the top view, and 
 
 wherein the first semiconductor laser element and the second semiconductor laser element are connected in series; 
 
 performing a first measurement, which comprises:
 supplying electric current to the first semiconductor laser element through the first and second parts of the first wiring and through the second wiring to measure at least one property of the first semiconductor laser element, the at least one property of the first semiconductor laser element including at least one of an electrical property or an optical property, and 
 supplying electric current to the second semiconductor laser element through the second wiring and the third wiring to measure at least one property of the second semiconductor laser element, the at least one property of the second semiconductor laser element including at least one of an electrical property or an optical property; 
 
 supplying electric current to both the first semiconductor laser element and the second semiconductor laser element through the first and second parts of the first wiring for a length of time; 
 performing a second measurement, which comprises:
 supplying electric current to the first semiconductor laser element through the first and second parts of the first wiring and through the second wiring to measure said at least one property of the first semiconductor laser element, and 
 supplying electric current to the second semiconductor laser element through the second wiring and the third wiring to measure said at least one property of the second semiconductor laser element; and 
 
 evaluating the first semiconductor laser element based on said at least one property of the first semiconductor laser element measured during the first measurement and the second measurement, and evaluating the second semiconductor laser element based on said at least one property of the second semiconductor laser element measured during the first measurement and the second measurement. 
 
     
     
       2. The method of manufacturing a light emitting device according to  claim 1 , wherein the at least one property of the first semiconductor laser element includes a forward voltage of the first semiconductor laser element, and the at least one property of the second semiconductor laser element includes a forward voltage of the second semiconductor laser element. 
     
     
       3. The method of manufacturing a light emitting device according to  claim 1 , wherein:
 each of the first semiconductor laser element and the second semiconductor laser element comprises a nitride semiconductor, and 
 the method further comprises, between the step of providing the light emitting device and the step of performing the first measurement, fixing a cap to the base to create a hermetically sealed space in which the first semiconductor laser element and the second semiconductor laser element are located. 
 
     
     
       4. The method of manufacturing a light emitting device according to  claim 1 , wherein the at least one property of the first semiconductor laser element includes a far field pattern of the first semiconductor laser element, and the at least one property of the second semiconductor laser element includes a far field pattern of the second semiconductor laser element. 
     
     
       5. The method of manufacturing a light emitting device according to  claim 1 , wherein in the step of supplying electric current for a length of time, the electric current is supplied to the first semiconductor laser element and the second semiconductor laser element connected in series. 
     
     
       6. The method of manufacturing a light emitting device according to  claim 1 , wherein the step of providing the light emitting device comprises:
 providing a first laser device comprising the first semiconductor laser element mounted on a first sub-mount, and 
 providing a second laser device comprising the second semiconductor laser element mounted on a second sub-mount, 
 simultaneously bonding the first laser device and the second laser device to the base via a bonding material by heating the bonding material without pressing the first laser device and the second laser device, the bonding material containing metal nanoparticles or metal sub-micron particles and an organic solvent. 
 
     
     
       7. The method of manufacturing a light emitting device according to  claim 1 , wherein:
 the light emitting device further comprises a sub-mount disposed between the second semiconductor laser element and the second wiring, and 
 the second wiring and the sub-mount are connected to each other by a wire. 
 
     
     
       8. The method of manufacturing a light emitting device according to  claim 7 , further comprising, after performing the second measurement, disconnecting the wire connecting the second wiring and the sub-mount by supplying electric current that is equal to or greater than a certain amount to the wire. 
     
     
       9. The method of manufacturing a light emitting device according to  claim 1 , wherein the first semiconductor laser element is inspected before being electrically connected to the first wiring and the second wiring, and the second semiconductor laser element is inspected before being electrically connected to the second wiring and the third wiring. 
     
     
       10. The method of manufacturing a light emitting device according to  claim 1 , wherein, in the step of performing the first measurement, a value of the electric current is gradually increased. 
     
     
       11. A method of manufacturing a light emitting device, the method comprising, in this order:
 providing the light emitting device, which comprises:
 a base comprising a first wiring, a second wiring, and a third wiring, 
 a first semiconductor laser element electrically connected to the first wiring and the second wiring, at an upper surface side of the base, and 
 a second semiconductor laser element electrically connected to the second wiring and the third wiring, at the upper surface side of the base, 
 wherein the base comprises a frame surrounding the first semiconductor laser and the second semiconductor laser in a top view, 
 wherein the first wiring comprises:
 a first part that is located at an upper surface of the base at a location inward of the frame, and 
 a second part that is exposed at a location outward of the frame in the top view, and 
 
 wherein the first semiconductor laser element and the second semiconductor laser element are connected in series; 
 
 performing a first measurement, which comprises:
 supplying electric current to the first semiconductor laser element through the first and second parts of the first wiring and through the second wiring to measure at least one property of the first semiconductor laser element, the at least one property of the first semiconductor laser element including at least one of an electrical property or an optical property, and 
 supplying electric current to the second semiconductor laser element through the second wiring and the third wiring to measure at least one property of the second semiconductor laser element, the at least one property of the second semiconductor laser element including at least one of an electrical property or an optical property; 
 
 evaluating the first semiconductor laser element based on said at least one property of the first semiconductor laser element measured during the first measurement, and evaluating the second semiconductor laser element based on said at least one property of the second semiconductor laser element measured during the first measurement; and 
 supplying electric current to both the first semiconductor laser element and the second semiconductor laser element through the first and second parts of the first wiring for a length of time. 
 
     
     
       12. A method of manufacturing a light emitting device, the method comprising, in this order:
 providing the light emitting device, which comprises:
 a base comprising a first wiring, a second wiring, and a third wiring, 
 a first semiconductor laser element electrically connected to the first wiring and the second wiring, at an upper surface side of the base, 
 a second semiconductor laser element electrically connected to the second wiring and the third wiring, at the upper surface side of the base, and 
 a sub-mount disposed between the second semiconductor laser element and the second wiring, 
 wherein the first semiconductor laser element and the second semiconductor laser element are connected in series, and 
 wherein the second wiring and the sub-mount are connected to each other by a wire; 
 
 performing a first measurement, which comprises:
 supplying electric current to the first semiconductor laser element through the first wiring and the second wiring to measure at least one property of the first semiconductor laser element, the at least one property of the first semiconductor laser element including at least one of an electrical property or an optical property, and 
 supplying electric current to the second semiconductor laser element through the second wiring and the third wiring to measure at least one property of the second semiconductor laser element, the at least one property of the second semiconductor laser element including at least one of an electrical property or an optical property; 
 
 evaluating the first semiconductor laser element based on said at least one property of the first semiconductor laser element measured during the first measurement, and evaluating the second semiconductor laser element based on said at least one property of the second semiconductor laser element measured during the first measurement; and 
 disconnecting the wire connecting the second wiring and the sub-mount by supplying electric current that is equal to or greater than a certain amount to the wire. 
 
     
     
       13. The method of manufacturing a light emitting device according to  claim 12 , further comprising, after evaluating the first semiconductor laser element:
 supplying electric current to the first semiconductor laser element and the second semiconductor laser element for a length of time; 
 performing a second measurement, which comprises:
 supplying electric current to the first semiconductor laser element through the first wiring and the second wiring to measure said at least one property of the first semiconductor laser element, and 
 supplying electric current to the second semiconductor laser element through the second wiring and the third wiring to measure said at least one property of the second semiconductor laser element; and 
 
 evaluating the first semiconductor laser element based on said at least one property of the first semiconductor laser element measured during the first measurement and the second measurement, and evaluating the second semiconductor laser element based on said at least one property of the second semiconductor laser element measured during the first measurement and the second measurement 
 wherein disconnecting the wire connecting the second wiring and the sub-mount is performed after performing the second measurement.